psychologists say take a RELAXING day with no practice every week at least to let ur subconcious brain get used to the piece.
that's right, i heard that too;
only 15% of out brain is devoted to our consciencem other works without our control - i often solve problems in a
lazy way - go to bed and wait for the
aha! to come.
i play ragtime and when i'm outside, taking care of some serious business, like mowing or moving lumber, dirt or stones or whichsoever heavy job and then i find myself in front of piano, the keys feel lighter* and i can play faster as i can follow all the notes** (i actually play without notes).
on the other side, when i play quake for an hour or two and then i start playing the piano, i hit nothing. a healthy mind would expect vice versa, t.i. to be snaily when doing snaily things and to be fast when making a
non-followable massacre among 15 other massacrers (lol

).
and sometimes it's just a day that you wouldn't hit the key even if the piano had organ's foot keyboard...
* that's probably very mine problem as i've been on synthesizer for 6 years and got used to very light keys and then switched to piano... but i don't believe that's true as i really got used to it in 4 years.
** i've calculated notes-per-second ratio in one of my favourite ragtimes - 3215 (counted it one by one(been bored
)) notes in 3-4 minutes, that is around 12 - 18 notes per second. it is not so fast, but you don't see a note in a stave without 2 - 3 notes upper or lower 